I use an electric toothbrush and electric razor all the time when boondocking. Our comfort level when boondocking is close to what it is when we are at home in our stick house ... except for short showers and use of paper plates/bowls/cups.
I charge the toothbrush, the shaver, the iPad, and the cell phones from our coach batteries with them plugged into a small inverter that is plugged into a 12 volt receptacle in the motorhome. There is no need to run the generator just for charging small items ... use it only to periodically charge the big coach batteries.